Gun sight



J. B. HEN DERSQN 4,825

Filed June 23. 1920 3 MIMI] I Patented Sept. 18, 1928.

JAMES BLAGKLOCK HENDERSON, E LEE, ENGLAND.

, GUN SIGHT.

Application filed June 23, 1920, Serial No. 391,188, and in GreatBritain September 19, 1919.

This invention relates to improvements in methods of directingprojectiles from guns, bomb-droppers and the like for use on board shipor other moving platforms upon which it is impossible to use a bubbletube to determine the vertical. In this invention I compensate the errorinv the trajectory due to angular motion of. the platform round the lineof sight to "the target, by laying an auxiliary telescope which isattached to the main gun sight, upon the horizon or'other distantobject, the sight being mounted upon trunnionsparallel to the axis ofthe gun and the cross-levelling adjustment being made by rotating thesight round this trunnion.

V Figure 1 shows an elevation of the sight looking parallel to the axisof the gun;

j Figure 2 shows 'a side elevation at right angles to Figure 1; and g 5Figure 8 is a vertical section through the focal plane of thecross-levelling telescope.

1 The sight is mounted upon the gun'trunnion 1 upon a fork 2 upon whichit is pivoted 011 a trunnion 3 which is parallel to the axis of the gun.The gun is turned about the .trunn'ion 3 by a worm 4: carried by abracket 5 which is attached to the fork 2, the worm t being turned bythe hand wheel 6 and gearing with the worm sector 7, which isrigidlyattached to the sight support 8 to which the trunnion 8 is attached.support 8 is made in two parts, the upper part .9 being pivoted on thelower part8 upon a centralpivot 10 shown dotted, the upper part 9 beingturned about this pivot 10 to'provide deflection in azimuth on thesight, a deflection scale 11 being graduated on the stem 9. p p

' The stem 9 carries a ring 12w'hicl1 supports the main sightingtelescope 13 upon 4 horizontal trunnions ,1&-15, this telescope beingelevated by a'c'rank '16 fitted with a worm sector 17, which is turnedby the worm 18 carried by a bracket 19, which forms a projecting part ofthe ring 12; The worm is turned by the hand wheel 20, the motion of thehand wheel 20 being recorded on a range dial which is not shown in thediagram. The support 9 carries, above the ring 12, a telescope holder 21which supports the telescope V 22, which I call the crosslevellingtelescope. It is provided with a cross-wire in I I the focal plane andthis cross-wire islaid upon the horizon by turning the hand wheel 6.

A section through the focal plane of the telescope 22 is shown in Figure3, the grati- The sight stem or cule 28, having a cross-wire 24 engravedupon it, is carried in a ring 25' upon'a' vertical stem 2627,the lowerstem 26 being square insection to prevent the ring 25 turning inazimuth. The rlng 25 is raised and low' fered by means of a screw '28and spring. 29,.

and a pointer 30, attached to the milled head 28 indicates the motionupon a scale 31,

. which is called the scale of drift.

The operation of the sight isas follows The hand wheel 20 having beenset to the given range the gun'is elevated and trained by the gun layerin the usual manner until the telescope 13 is on the target. Anauxiliary observer looking through the telescope 22' .turns the handwheel Guntil the telescope 22 is laid upon the horizonor upon anyconvenient object near the horizon. For example, in aircraft it might belaid upon a very distant low-lying cloud. I shall call thetwo ob- 7servers A and B, A-being the main gun layer.

After .13 has brought the telescope 22 on to the horizon, A may findthat his telescope is no longer on the target and he trains and elevatesthe gun so as to bring it on to the target again. The two observersWorking together, one on the horizonjand the other on the target,automatically compensate the defiection of the trajectory which wouldotherwisebe brought about by the angular motion of the platform aroundthe line of sight to the target. The adjustment for drift is made byinclining the axis of collimation of the telescope 22 to the centralline of the sight stem 8, which corresponds to the standard method ofapplying drift by varying the inclination of the plane of elevation ofthe sight to the axis of the gun trunnion.

I have described the invention as applied to a gun sight, but it isequally applicable to a director sight for controlling guns at a,

distance, the trunnion 1 being'the main horizontal trunnion of thedirectorsight.

I have also shown and described the sight 13 and 22 as being telescopicsights but it is to be understood that either or both of these might beof the open or othertype;

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. In a sighting apparatus for a gun mounted on anangularly moving platform, a sighting member adapted to bear apredetermined relation to a line between the gun and a distant object, amember connected to said sight tant object, aimember connecte ing memberand bearing V predetermined relation'to the hereof the gun, anda.continuously efi'ective sighting member lying at a substantial angle tothe first sighting rnember and connected to said members whereby theymay be continuously maintain ed in a vertical plane as the platformmoves to compensate for the effect of its angular movement, t

2. Ina sighting apparatus for a gun mounted on an angularlymovingplatform, a sight ing member adapted to bear apred'eternnnedrelation to a line betweenqthe un and a dis:

i-ng member and bea-ring a predetermined relation o the bore of the ounmeans for ad-- justing'themembers with respect to each other inaccordance ivith jthe'range adjust ,,ment of the gun,an d meansincluding an optical instrument connected to said members forcontinu'ouslyivicwing,a distant 'pointatan angle to, said line Wherebyone member m ay be continuouslyoscillated about the other as theplatform ,moves to compensate for the e'fiec't ofiits angular movement.

'* 7 3 Inasighting apparatus for a gun mounted on angularlyniovingplatit'orlma member. adapted to bear a predeterminedrelation toaline between the gun and a target, a. memberconnected, tov said memberandbearing a predetermined relationto the bore of the gun, means foradj'ustingthe members with respect to eachother in accordance with, therange v adjustment of the. gun,}means included in said:

conneetion lfor adjusting the members with respect to each otherinaccordance with C19? fleetion andan opticalginstrument -eonnectedmoves to; c

to said members for viewing continuously a distant point at-an angle tothe said line whereby Qne nembe maybe nt u u y" oscillatedaboutjtheother as the platform mpensa'te for the effect of angularmovement e 5 v4, In asighting apparatusfor a gun mount ed on anangularlvmovingplatform, a mem;

ber' para-llelftol the bore bf the gun, a main sighting device connectedto andflrotatable' about said member, an auxiliary sightingdeviceconnected to said main sighting-device,

means assoc-iated with the auxiliary sighting device for EIlt'GIfIQgJtSaxis of collimation relasv tive to the axis of collimation ofthe mainsightingdevic'e and means whereby the main sighting device and themember'parallel to to said sightdevicef 'the'bore of the gun may beretained in a ver tieal ipianflby "viewing ae distant point through theauxiliary sighting device. 7 v n 5, I nas'ighting aaratUsfQragunmountedon an angular-1ymoving 'platform,amem-' be'r having a predeterminedrelation to the bore of the gun, a sighting deviceconnected to themember for-viewing a distant point, a s'econd sighting device connectedto the first ighting device for vie n a stan P in at an angle to theline between the gun and thefdi stant object, whereby the first sightingdevice a d the memberin ay' be maintained in nee-ted to'sa-id firstdevice for v ewinga dis tant point at an angle tosaidline meanjs tomaintain said first devi ce substantially immovable as the platformmoves by keep ngsaid second device direotdon said point, a,nd

means for introducing a drift correction by;

apparatus for agun mount ed on anangulaidy mov ng platform, a sightadjusting the relation between thela-xesoi" collimation of said devices;

In a eh p a atus or su meu'n A ed on an angular ymovingeplatform, a, sihtthe'vertieal plane of the bore of the gun, a

second sighting device conne oted at an'anglef: v to said device for vewing a distant -ob1ect,

means maintain said first devise substani tlally immovable by keepingsaid second'deviee directed saidpoint, and means cons .ne'eted tothesecond swhting device for. in-;

troducin drift, correctlons.

V 8. In "combination W ith'the trunnion ofia" gun, a support connectedtov said trunnion to pivot about an axis parallel to the borelo'f 'ingdevice,mounted-substantiallv paralle to the gun, means for adjustingsaid support about saida-Xis, a sighting deviee on said support havingrtslme of ght 111F773. plane passing through sa d ams, and asecondsighting deof sight atanangle to said axis.

' Dat d t e 1 t y M y, 92

vice mounted onfsaid supporthalving its line; t V i JAMESBLACKLQCKnnnnnn'son.

loo 7

